1. Field of the Invention
This invention relates to a process for separating alkali metal compounds from a polymer. More particularly, this invention relates to a method for removing alkali metal compounds from a polymer comprising a conjugated diolefin and/or an alkenyl aromatic hydrocarbon monomer unit.
2. Prior Art
Heretofore, several methods have been proposed for separating certain alkali metal compounds, particularly lithium compounds from a polymer, particularly a conjugated diolefin polymer. In general, these methods involve contacting the polymer and alkali metal-containing composition with water and/or an acid. A principal problem associated with these methods is that each introduces an impurity into the polymer which must be removed before the polymer is suitable for at least most end use applications. These methods, then, add a rather complicated separation step to the processes. While the separation processes may be reasonably successful they frequently result in at least a small amount of impurity remaining in the polymer composition. Also, the separation step is an added, rather complicated, step in preparing the polymer composition for its various end use applications. The need, then, for a process which will separate alkali metal compounds, particularly lithium compounds, from a polymer comprising a conjugated diolefin and/or an alkenyl aromatic hydrocarbon monomer without introducing impurities thereto and without introducing a rather complicated "clean-up" or purification step is believed to be readily apparent.